The present invention relates generally to tape drives which use a removable cartridge having a storage tape. More specifically, the present invention relates to a buckle for a tape drive and cartridge that minimizes the likelihood of leader runaway.
Tape drives are widely used for storing information in digital form. These tape drives commonly use a storage tape having a thin film of magnetic material which receives the information. Typically, the storage tape is guided with a plurality of tape guides between a pair of spaced apart reels, past a data transducer. The data transducer records information onto the moving storage tape and/or reads information from the moving storage tape.
In one type of tape drive, one of the reels is part of the tape drive, while the other reel is part of a removable cartridge. For this type of tape drive, the reel that is a part of the tape drive is commonly referred to as a take-up reel, while the reel that is a part of the cartridge is commonly referred to as a cartridge reel. With this system, upon insertion of the cartridge into the tape drive, it is necessary to couple the storage tape on the cartridge reel to the take-up reel of the tape drive. Subsequently, the storage tape must be uncoupled from the take-up reel, prior to removing the cartridge from the tape drive.
Typically, a cartridge leader on the storage tape is automatically coupled to a drive leader that is connected to the take-up reel during insertion of the cartridge into the tape drive. The procedure of connecting the drive leader to the cartridge leader is commonly referred to as xe2x80x9cbucklingxe2x80x9d or xe2x80x9ccouplingxe2x80x9d. Subsequently, during ejection of the cartridge, the cartridge leader is unbuckled from the drive leader.
FIGS. 1A and 1B illustrate a prior art cartridge leader 10P and a prior art drive leader 12P at two alternate positions during coupling. In particular, FIG. 1A illustrates the prior art leaders 10P, 12P prior to coupling and FIG. 1B illustrates the prior art leaders 10P, 12P coupled together. In this prior art embodiment, the cartridge leader 10P includes a hoop portion 14P and a slot portion 16P, while the drive leader 12P includes a tab 18P having a nose 20P and a neck 22P. The nose 20P includes a pair of proximal, opposed edges 23P that extend away from the neck 22P, substantially perpendicular to the neck 22P. Stated another way, the nose 20P includes a pair of opposed ears 24P that cantilever away from the neck 22P
The hoop portion 14P is dimensioned to enable the nose 20P and neck 22P of the drive leader 12P to pass therethrough. The slot portion 16P is dimensioned to receive the neck 22P, but prevent the ears 24P of the nose 20P from passing therethrough. Buckling of the two leaders 10P, 12P is done by initially tucking the tab 18P within the hoop portion 14P as illustrated in FIG. 1A and subsequently pulling the drive leader 12P until the neck 22P slides into the slot portion 16P of the cartridge leader 10P as illustrated in FIG. 1B.
FIG. 1C illustrates a prior art buckler 26P that automatically couples the prior art cartridge leader 10P of a cartridge 28P to the prior art drive leader 12P. With this system, the prior art buckler 26P includes a hook 30P that fits into a drive leader aperture 32P (illustrated in FIGS. 1A and 1B) in the drive leader 12P.
The design illustrated in FIG. 1C utilizes the movement of the cartridge 28P into and out of the tape drive to buckle and subsequently unbuckle the cartridge leader 10P and the drive leader 12P. More specifically, with this system, the hook 30P is rotated by the cartridge 28P during insertion of the cartridge 28P into the tape drive. At the same time, a take-up motor pulls the drive leader 12P away from the cartridge 28P. If the leaders 10P, 12P are in good condition and are properly positioned, the neck 22P of the drive leader 12P slides into the slot portion 16P of the cartridge leader 10P and both ears 24P slide behind the slot portion 16P to successfully couple the leaders 10P, 12P. Commonly assigned U.S. Pat. Nos. 4,662,049 and 4,720,913 provide a detailed discussion of this type of tape buckling arrangement.
Unfortunately, this type of buckling operation provides only one opportunity to couple the leaders 10P, 12P. The buckling operation will be successful if the leaders 10P, 12P are in good condition and are properly positioned. However, one or both of the leaders 10P, 12P may not be in the proper position for coupling. For example, the cartridge leader 10P may not be in the correct position if the cartridge 28P is inserted too slowly or too quickly into the tape drive. Additionally, the cartridge leader 10P may be damaged from improper or excessive use and may not be in the correct position. If one or both of the leaders 10P, 12P are not in the correct position, the leaders 10P, 12P may not securely couple. For example, only a portion of the tab 18P, e.g. only one of the opposed ears 24P, may be positioned within the hoop portion 14P. In this situation, as the neck 22P of the drive leader 12P slides into the slot portion 16P of the cartridge leader 10P, only one of the ears 24P is positioned behind the slot portion 16P of the cartridge leader 10P. This situation is commonly referred to as a xe2x80x9chalf-ear situationxe2x80x9d.
With the design outlined above, the hook 30P releases the drive leader 12P upon insertion of the cartridge 28 even if the leaders 10P, 12P are only partly coupled. Subsequently, during movement of the leaders 10P, 12P towards the take-up reel, the partly coupled leaders 10P, 12P can become uncoupled. This will cause the drive leader 12P to retract onto the take-up reel. This is commonly referred to as xe2x80x9cleader runawayxe2x80x9d. Unfortunately, after leader runaway occurs, the tape drive must be disassembled to reposition the drive leader 12P on the hook 30P. This can be very expensive. Further, the tape drive can""t be used until the drive leader 12P is repositioned on the hook 30P. This can be very inconvenient to the customer because of the down time of the tape drive.
Currently, tape drives are being developed that test whether the leaders are securely coupled prior to the buckler releasing the drive leader. In particular, U.S. patent application Ser. No. 09/515,461, by Kumar Kasetty, entitled xe2x80x9cBUCKLING SYSTEM FOR A TAPE DRIVExe2x80x9d, filed concurrently herewith and assigned to Quantum Corporation discloses a buckling system that provides multiple opportunities to couple the drive leader to the cartridge leader. The buckling system includes a detector for testing whether coupling was successful prior to the buckler releasing the drive leader. The contents of U.S. patent application Ser. No. 09/515,461 are incorporated herein by reference.
Unfortunately, a partly coupled leader can fool the detector. More specifically, in a half-ear situation, one of the ears 24P of the drive leader 12P can retain the cartridge leader 10P sufficiently to fool the detector. Subsequently, however, the one ear 24P can release the cartridge leader 10P during movement of the leaders 10P, 12P past the tape guides and transducer. This will cause leader runaway.
In light of the above, it is an object of the present invention to provide a buckle for a tape drive and cartridge that resists half-ear situations and other situations in which the leaders are only partly coupled. Another object is to provide a tape drive that automatically and reliably couples and de-couples the storage tape to the take-up reel. Still another object is to provide a tape drive having an improved drive leader that minimizes the likelihood of leader runaway. Another object is to provide a tape drive which is compatible with prior art cartridges.
The present invention is directed to a combination of a tape drive and cartridge that satisfies these objectives. The tape drive and cartridge include an improved buckle that couples a drive leader of the tape drive to a cartridge leader of the cartridge. The buckle includes a first buckle component that is secured to one of the leaders and a second buckle component that is secured to the other leader. The first buckle component includes a receiver having a slot portion and a hoop portion. The second buckle component includes a tab that engages the receiver to couple the buckle components and the leaders.
The tab has a nose and a neck. The nose is sized and shaped to fit within the hoop portion but not the slot portion of the receiver. The neck is sized and shaped to fit within both the hoop portion and the slot portion of the receiver. The nose includes a pair of opposed proximal edges that cantilever away from the neck and engage the first buckle component to couple buckle components.
Importantly, at least one, and more preferably both, of the opposed proximal edges are curved or arc shaped. As a result of this shape, the cartridge leader will not move with the drive leader unless both proximal edges of the nose are tucked behind the slot portion of the receiver. Stated another way, with this design, the tab will release the receiver if only one of opposed proximal edges is engaging the receiver. This reduces the likelihood of a half-ear situation resulting in leader runaway.
The present invention is also directed to a method for coupling a drive leader of a tape drive to a cartridge leader of a cartridge. The method includes the step of providing a first buckle component and a second buckle component. The second buckle component includes a nose having opposed proximal edges that are curved. As discussed above, this inhibits half-ear situations, reduces the likelihood of leader runaway and improves the reliability of the tape drive.